Profiler notifications (#640)

* Initial changes for adding lost event notifications

* Handling polling errors by notifying listeners

* Restructuring lost events & testing

* Minor fixes to tests

* Add back in filtering

* Changing how lost events are found

* Cleaning up tests

src/Microsoft.SqlTools.ServiceLayer/Profiler/Contracts/ProfilerEventsAvailableNotification.cs

@@ -14,6 +14,8 @@ namespace Microsoft.SqlTools.ServiceLayer.Profiler.Contracts
         public string OwnerUri { get; set; }
 
         public List<ProfilerEvent> Events { get; set; }
+
+        public bool EventsLost { get; set; }
     }
 
     public class ProfilerEventsAvailableNotification

src/Microsoft.SqlTools.ServiceLayer/Profiler/Contracts/ProfilerSessionStoppedNotification.cs

@@ -0,0 +1,25 @@
+//
+// Copyright (c) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE file in the project root for full license information.
+//
+
+using System.Collections.Generic;
+using Microsoft.SqlTools.Hosting.Protocol.Contracts;
+using Microsoft.SqlTools.ServiceLayer.Utility;
+
+namespace Microsoft.SqlTools.ServiceLayer.Profiler.Contracts
+{
+    public class ProfilerSessionStoppedParams
+    {
+        public string OwnerUri { get; set; }
+
+        public int SessionId { get; set; }
+    }
+
+    public class ProfilerSessionStoppedNotification
+    {
+        public static readonly
+            EventType<ProfilerSessionStoppedParams> Type =
+            EventType<ProfilerSessionStoppedParams>.Create("profiler/sessionstopped");
+    }
+}